Bird cage



FIG. 1 is a perspective view of a bird cage showing my new design.

FIG. 2 is a front elevational view thereof.

FIG. 3 is a rear elevational view thereof.

FIG. 4 is a right side elevational view thereof.

FIG. 5 is a left side elevational view thereof.

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines shown in the drawings depict portions of the bird cage that form no part of the claimed design. 

CLAIM I claim the ornamental design for a bird cage, as shown and described. 